Improvement in plastic compositions for the manufacture of knobs and other molded



UNITED STATES PATENT OFFIon.

HENRY E. SHEPARD, OF NEW HAVEN, ASSIGNOR TO BRADLEY AND HUBBARD, OF WEST MERIDEN, CONNECTICUT.

IMPROVEMENT IN PLASTIC COMPOSITIONS FOR THE MANUFACTURE OF KNOBS AND OTHER MOLDED ARTICLES.

Specification forming part of Letters Patent No. 140,735, dated July 8, 1873 application filed February 21, 1873.

To all'whom-it may concern:

. Be it known that I, HENRY E. SHEPARD, of New Haven, in the county of New Haven and State of Connecticut, have invented a new Composition for the Manufacture of Knobs and other articles; and I do hereby declare the following to be a full, clear, and exact description of the same.

This invention relates to a new composition for the manufacture of knobs, and for other purposes, such as tape-measure cases, articles of stationary, 850., the object being chiefly to produce a material in imitation of shell; and it consists in combining mica and shellac, with or without coloring matter, as more fully hereinafter described.

I take mica and break it into small pieces or particles, using the Waste or scrap for this purpose, and mix this with shellac reduced to a liquid state until it assumes about the consistency of soft putty, then roll it into sheets or other convenient form for molding. The molds or dies are prepared in substantially the usual manner for other compositions. From this sheet or mass I take the requisite quantity and varnish the surface with a shellac varnish, the object of this varnishing being to prevent the particles of mica rising from or appearing directly upon the surface then, placed in the dies, the material is pressed into form in substantially the usual manner; then, when cooled; it is very much harder and tougher than other compositions of which shellac forms the basis; and the same quantity of material requires less shellac, because the mica absorbs no portion of the shellac, and when completed the article is almost a perfect imitation of shell.

If desirable, color may be added to give any required tint.

This composition is peculiarly adapted to the manufacture of knobs, tape-measure cases, and articles of stationery, toys, games, and generally to all articles for which similar compositions are now used.

I do not wish to be understood as claiming mica as an ingredient for the manufacture of varnish.

I claim as my invention The composition herein described for the manufacture of articles, consisting of shellac and mica, prepared for molding, substantially as set forth.

Witnesses: HENRY E. SHEPARD.

A. CHAMBERLAIN, J r., E. A. WILsoN. 

